NAO robot: porting ALSoundExtractor to qi framwork

Question

When porting from NAOqi to qi framework I achieved a partial success. I do however still have the following problem. I do not know how to implement sound processing with ALSound

Answer 1

To use this API, you must write a Qi Service that advertises this method:

void processRemote(
    int nbOfChannels,
    int nbrOfSamplesByChannel,
    const qi::AnyValue& timestamp,
    const qi::AnyValue& buffer)
{
  std::pair charBuffer = value.unwrap().asRaw();
  const signed short* data = (const signed short*)charBuffer.first;
  // process the data like in the example.
}

Note that with the Qi framework:

• AL::ALValue is replaced by qi::AnyValue. Getting the binary data (aka "raw") is slightly different.
• AL_SOUND_FORMAT is replaced by signed short*.
• ALSoundExtractor is not available, so we needed to do the conversion to const AL_SOUND_FORMAT* by ourselves.

Say your service is registered as "MySoundExtractor", you will have to tell ALAudioDevice to start the sound extraction and send the data to your service as follows:

auto audio = session->service("ALAudioDevice").value();
int nNbrChannelFlag = 0; // ALL_Channels: 0,  AL::LEFTCHANNEL: 1, AL::RIGHTCHANNEL: 2; AL::FRONTCHANNEL: 3  or AL::REARCHANNEL: 4.
int nDeinterleave = 0;
int nSampleRate = 48000;
audio->setClientPreferences("MySoundExtractor", nSampleRate, nNbrChannelFlag, nDeinterleave);
audio->subscribe("MySoundExtractor");

Note that I did not test this code, so let me know what may be wrong.